a) till 15k single bill value, you can get 5% using amazon pay voucher with SBI cashback credit card via amazon bill pay
b) more than 15k single bill, you can probably get around 1% to 2.5% based on debit cards or credit cards you use
these are the things I can think of
any other answers will greatly help too:)
anyone else? your inputs
Tataneu... infinity card gives 5% neucoins